VALVE, ESPECIALLY FOR BOTTLES FOR ULTRA-HIGH PURITY GAS

摘要

A valve for pressurized or liquefied gas comprises a valve body (12) with a gas flow channel (16) and in this channel a sealing seat (30) for an open/close element (32) having a free end (60) where a shoulder (62) is provided. An annular seal (64) is mounted on the free end (60) of the open/close element (32), the annular seal (64) having a front end face (66) facing the sealing seat (30) and a rear end face (68) resting on the shoulder (62) of the open/close body. A holding ring (70) surrounds the annular seal (64) circumferentially and comprises a radial lip (72) that bears on the outer edge of the front end face (66) of said annular seal (64). The annular seal (64) includes an outer annular shoulder (74) on the edge of its front end face and the radial lip (72) with the holding ring (70) has an annular bead (76) facing this outer annular shoulder (74) of the annular seal (64). The holding ring (70) is fixed to the open/close element (32) by a leaktight outer circumferential weld (77), so that the annular bead (76) passes axially into the outer annular shoulder (74) of the annular seal (64) to compress it.